Bridging cam for limiting the position of welt needles in a knitting machine

ABSTRACT

Camming for controlling the operation of needles in a knitting machine is provided in a raceway, other than a raceway including a wing and stitch cam, with a bridging cam effective to prevent the welt needles from moving toward a tuck or knit position when they are between the wing and stitch cam.

United States Patent Christopoulos et al. July 8, 1975 [54] BRIDGING CAM FOR LIMITING THE 3,572,056 3/197! Radin M 66/50 A A 3,595,033 7/l97l Agulnek... 66/57 gf gfiig IN 3,6l4,877 l0/l971 Radin 66/50 A 3,696.64] 10/]972 Sumitomo... M 66/40 Inventors: John Christopoulos, Brentwood, 3,780,539 12/l973 Mishcon 66/50 A N.Y.; Lester Mishcon, Miami Beach,

Fla,

Assignee: The Singer Company, New York,

Filed: Nov. 12, I973 Appl. No.: 415,035

US. CI. 66/40 Int. Cl. D04B 9/00 Field of Search .A 66/78, 38, 50 R, 57, 25,

References Cited UNITED STATES PATENTS 1/195] Mishcon et a]. 66/50 A Primary Examiner-W. C. Reynolds Assistant ExaminerA. M, Falik Attorney, Agent, or FirmMarshall J. Breen; Chester A. Williams, .Ir.; William V. Ebs

[57] ABSTRACT Camming for controlling the operation of needles in a knitting machine is provided in a raceway, other than a raceway including a wing and stitch cam, with a bridging cam effective to prevent the well needles from moving toward a tuck or knit position when they are between the wing and stitch cam.

10 Claims, 7 Drawing Figures PATENTED JUL 8 ms Fig.5

SHEET 1 BRIDGING CAM FOR LIMITING THE POSITION OF WELT NEEDLES IN A KNITTING MACHINE FIELD OF THE INVENTION The invention relates to knitting machines and more particularly is directed to the construction of needle controlling camming for such machines.

DESCRIPTION OF THE PRIOR ART Knitting machines wherein a wing and stitch cam are provided at feeds around the machine are well known in the knitting machine art. In such machines, needles which are supposed to welt at any particular feed (that is pass by the feed without taking yarn) may, while between the wing and stitch cam, be pulled out of the welt position by stitches they are holding and (in the case of dial needles) by centrifugal force into positions such that they are caused to take yarn. Also, as such needles move out of position they act against yarn being fed to adjacent knit and/or tuck needles. That is, the welt needles in the absence of applicants bridging cam may be pulled upwardly while between the wing and stich cam and the tops of the hooks of these needles caused to strike and alter somewhat the directional line along which yarn is supposed to be fed to knit and tuck needles whereby such needles may fail to take yarn and form a stitch. As a consequence the yarn frequently fails to enter these adjacent needles and they drop stitches. With either welt needles or both welt and adjacent knit and/or tuck needles operating improperly because of the welt needles being pulled out of position an imperfect cloth is produced.

SUMMARY OF THE INVENTION In order to prevent needles which are supposed to welt at any particular feed of a knitting machine from being moved from their welt position toward a yarn accepting position, needle controlling camming is provided at each feed with a bridging cam, in a raceway other than a raceway including the wing and stitch cam, to at least span and preferably extend beyond the gap between the wing and stitch cams and so define a limiting position for butts on such needles.

DESCRIPTION OF THE DRAWINGS FIG. I is a front elevational view showing the cam side of a dial cam section, according to the invention, for a circular knitting machine;

FIG. 2 is a side elevational view showing latch needles for use in a circular knitting machine provided with dial cam sections as illustrated in FIG. 1',

FIG. 3 is a side elevational view of the cam section of FIG. 1;

FIG. 4 is a sectional view taken on the plane of the line 44 of FIG. 1;

FIG. 4A is a fragmentary sectional view taken on the plane of the line A-A of FIG. 4;

FIG. 5 is a front elevational view showing the cam side of a dial cam section, according to a modified form of the invention, for a circular knitting machine; and

FIG. 6 is a front elevational view showing the cam side of a dial cam section, according to another modified form of the invention, for a circular knitting machine.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2 of the drawings reference 5 character 10 designates a dial cam section for one feed of a circular knitting machine. As shown such cam section includes raise cams l2, l4 and I6, guard earns 18, and 22, wing cam 24 and stitch cam 26. Reference characters 28 and 30 designate latch type knitting needles of a kind suitable for use in the dial of a knitting machine which includes cam sections as shown in FIG. 1. Such needles are each provided with a correspondingly located butt 32 which is operable in a raceway extending between raise cam 12 and guard cam 18, and over or under wing cam 24. Each such needle also includes another butt which in some needles, of which needle 28 is an example, is a butt 34 disposed to operate in a raceway defined by raise cam 14 and guard cam 20, and in other needles of which needle 30 is an example in a butt 36 disposed to operate in a raceway defined by raise cam 16 and guard cam 22.

The raise cams l4 and 16 are rendered adjustable as in the manner disclosed in U.S. Pat. No. 3,456,460 for Cylinder and Dial Knitting Machines issued July 22, 1969. The raise cam I4 is formed on a member 38 which is integral with guard cam 20 and which is slidable in cam section 10 in a track 40 that is parallel to the cam 14. Similarly raise cam 16 is formed on member 42 which is integral with guard cam 22 and which is slidable on track 44 in the cam section. Member 38 includes a toothed portion 46 which meshes with a pinion 48 and member 42 includes toothed portion 50 which meshes with pinion 52. Pinion 48 is affixed to one end of a shaft 54 which extends through the cam section 10 and has knob 56 secured to its other end. Pinion 52 is affixed to one end of shaft 58 which extends through the cam section 10 and has knob 60 secured to its other end. By turning knob 56 raise cam 14 may be positioned for raising needles with butts 34 to a knit position, or for raising such needles to a tuck position, or so as to permit such needles to welt. Similarly raise cam 16 may be positioned by knob 60 for raising needles with butts 36 to a knit position, or for raising such needles to a tuck position, or so as to permit such needles to welt. Guard cams 20 and 22 move with raise cams 14 and 16 respectively so that a constant spacing is maintained between each of these raise cams and its associated guard cam. Suitable means as indicated in the aforesaid U.S. Pat. No. 3,456,460 may be provided for holding raise cam 14 or raise cam 16 in any one of the stated positions into which it may be moved by turning the knob 56 or 60 respectively.

In a knitting machine needles move relative to the cam section 10 from right to left as viewed in FIG. I and cams of the cam section interact with the needle butts. Raise cam 12 interacts with butts 32 to move all needles part way toward a tuck or knit position, and depending upon its position, cam 14 interacts with butts 34 to further move needles 28 into either a tuck or knit position, or the cam fails to move needles 28 an additional distance and such needles welt. Depending upon its position, cam 16 interacts with butts 36 to further move needles 30 into either a tuck or knit position, or the cam fails to move the needles 30 beyond the position into which they are moved by raise cam 12 and such needles welt.

By way of example raise cam 14 is shown in a position to move needles 28 to a tuck position and raise cam 16 is shown in a position permitting needles 36 to welt, however such raise cams may be differently positioned, the particular positions selected for the cams in any cam section being determined by the type of fabric to be knitted.

Stitch cam 26 may be adjusted by screw 62 against the bias of spring 64, and moved in the directions in which it extends to a desired position according to the length of the stitch to be produced. In a cam section wherein at least some needles are moved to a knit or tuck position, the stitch cam is disposed to engage the butts 32 of all needles and move them to a cast-off position whether they are knit, tuck or welt needles. Wing cam 24 engages butts 32 of welt needles before they engage the stitch cam and moves them away from a yarn accepting position. The butts 32 of the welt needles are engaged by the end portion of the stitch cam after the wing cam and moved into the cast-off position. A gap 66 necessarily left between the wing and stitch cam for knit and tuck needles must be traversed by the welt needles in passing from the wing to the stitch cam and while such needles are between the wing cam (i.e. the trailing edge 67 of such cam) and the stitch cam, they are restrained in accordance with the invention from being moved toward the knit or tuck positions in response to forces exerted on the needles by stitches which they hold while knitting and/or centrifugal force. Such restraint is provided for with bridging cams 68 and 70. Bridging cam 70 in its operative position defines a limiting position for the butts 36 of needles 30 when raise cam 16 is in the position shown permitting needles 30 to welt, and bridging cam 68 in its operative position defines a limiting position for the butts 34 of needles 28 when raise cam 16 is correspondingly positioned to permit needles 28 to welt. Preferably the bridging cams are formed, as shown, to extend a greater distance beyond the wing cam than that merely necessary to limit the movement of needles while in the gap between the wing and stitch cam. The extra length, which may be such as to guard needles until they engage the raise cam (corresponding to cam 12) of the next adjacent cam section, serves to restrict movement of needles beyond the stitch cam when both adjustable raise cams in a cam section are disposed to permit needles to welt and the stitch cam of such section is disposed to miss the butts 32. This is the required disposition of cams in some cam sections for knitting a blister fabric.

The bridging earns 68 and 70 are formed on end portions of elongated members 72 and 74 respectively each of which is slidably mounted in cam section wherein they are retained by plates 76 and 78. Members 72 and 74 are each movable between a position where its bridging cam is operative and in contact with the adjacent guard cam (as shown for member 74, bridging cam 70 and guard cam 22), and a retracted position where the bridging cam is in position to avoid interference with the adjacent guard cam (as shown for member 72, bridging cam 68 and guard cam as the associated adjustable raise cam is moved into a position where it is effective to act on and dispose needles in a yarn accepting position. Suitable means are provided for defining and holding the bridging cams in their operative position. As shown in FIG. 4 such position defining and holding means includes a recess 80 in the elongated member on which the bridging cam is formed and a ball 82 which biased by spring 84 against the member and into the recess when the bridging cam is in its operative position. A recess 86 is also provided in the elongated member on which the bridging cam is formed to receive the ball 82 when the elongated member and bridging cam are in the retracted position. Elongated members 72 and 74 include offsets 88 and 90 respectively each of which engages the cam section surface 92 when the associated bridging cam is in its operative position and thereby prevents the bridging cam from being disposed in a position where it could engage the shank of a needle.

The modified cam section of FIG. 5 is generally similar to the cam section of FIGS. 1 and 3, and corresponding parts have been designated with corresponding reference characters, a prime mark however, having been added to the reference characters in FIG. 5. In the cam section 10' of FIG. 5, raise cam 14' is shown in a position to raise needles to a knit position. Otherwise the cam section 10' of FIG. 5 differs from the cam section 10 of FIGS. 1 and 3 only in the manner in which bridging cams are incorporated into cam section 10' and therefore the description of FIG. 5 is limited to such cams. In the construction of FIG. 5 the bridging cams which have been indicated by reference characters 94 and 96 are integral parts of the guard cams. Bridging cam 94 is an integral part of guard cam 20' and is movable with the guard cam 20 and raise cam 14'. The other bridging cam 96 is an integral part of guard cam 22' and is movable with the guard cam 22 and raise cam 16'. There is, therefore, no possibility of interference between the bridging cams and adjacent guard cams.

FIG. 6 shows a modified cam section which is generally similar to the cam sections of FIGS. 1 and 3 and wherein parts corresponding to the parts of FIGS. 1 and 3 have been designated with the same reference characters except for the addition of a double prime mark In the cam section 10" of FIG. 6, raise cam 14" is shown in a position permitting needles to welt. Otherwise cam section 10" of FIG. 6 differs from cam section 10 of FIGS. 1 and 3 only in the manner in which bridging cams are included in the cam section. In the construction of FIG. 6 the bridging cams which are denoted by reference characters 98 and 100 are stationary being affixed to the cam section 10" in the positions shown by screws I02 and 104 extending through integral extensions 106 and 108 of such cams and into the cam section. The fixed positions of the bridging cams 98 and 100 are such as to bring them into contact with guard cams 20" and 22" respectively when adjustable raise cam 14" associated with guard cam 20" and adjustable raise cam 16" associated with guard cam 22" are in positions as shown permitting needles to welt. When it is desired to move raise cam 14" into a position to cause needles to knit or into position to cause needles to tuck, bridging cam 98 is detached from cam section 10 so that it cannot interfere with movement of guard cam 20". Similarly when it is desired to move raise cam 16" into a position to cause needles to knit or into a position to cause needles to tuck bridging cam I00 is detached from cam section 10" so that it cannot interfere with movement of guard cam 22".

While the invention has been described in its preferred forms it is to be understood that the words which have been used are words of description rather than of limitation, and that changes within the purview of the appended claims may be made without departing from the true scope and spirit of the invention. in particular, it should be noted that while the invention has been described in the enviornment of dial camming it is equally applicable to cylinder camming. Means differing from the raise cams 14, 14', 14" and l6, l6, 16" may of course be utilized for moving needles to knit or tuck positions. A pattern wheel, for example, may be used in place of such raise cams to move cylinder needles into a knit or tuck position.

Having thus set forth the nature of this invention, what is claimed herein is:

l. in camming for a knitting machine, the combination comprising a wing cam; a stitch cam separated by a gap from the wing cam; a needle with a butt engageable by both said wing and stitch cams when the needle is permitted to welt, said needle being movable beyond the trailing edge of the wing cam and across said gap to the stitch cam, the needle also including another butt; and a bridging cam engageable with said another butt throughout movement of the needle between the trailing edge of the wing cam and the stitch cam whereby movement of the needle toward a knit or tuck position is restricted while the needle moves across said gap.

2. The combination of claim 1 wherein the bridging cam is of a length sufficient to be engageable with said another butt in positions of the needle beyond said gap.

3. The combination of claim 1 including an adjustable cam movable from a position permitting said needle to welt, into a position to engage said another butt of the needle and move the needle into a knit position or into another position to engage said another butt of the needle and move the needle into a tuck position; and a guard cam to limit the uncontrolled flight of said needle from the adjustable cam, said guard cam being movable with the adjustable cam; the bridging cam extending into the path of movement of the guard cam but being retractable into a position wherein interference with the guard cam is avoided.

4. The combination of claim 3 including means for holding the bridging cam in a retracted position.

5. The combination of claim 3 including means defining the operative position of the bridging cam.

6. The combination of claim 3 including means positively preventing any substantial movement of the bridging cam beyond an operative position.

7. The combination of claim 1 including an adjustable cam movable from a position permitting said needle to welt into a position to engage said another butt of the needle and move the needle into a knit position or into another position to engage said another butt of the needle and move the needle into a tuck position;

and a guard cam to limit the uncontrolled flight of said needle from the adjustable cam; said guard cam and bridging cam being affixed to and movable with the adjustable cam.

8. The combination of claim 1 including an adjustable cam movable from a position permitting said needle to welt into a position to engage said another butt of the needle and move the needle into a knit position or into another position to engage said another butt of the needle and move the needle into a tuck position; and a guard cam to limit the uncontrolled flight of said needle from the adjustable cam, said guard cam being movable with the adjustable cam and the bridging cam extending into the path of movement of the guard cam; and cam section means for supporting all of the cams; the bridging cam being affixed to and stationary on said cam section means but being detachable therefrom to permit its removal from the path of movement of the guard cam.

9. The combination of claim 1 including an adjustable cam movable from a position permitting said needle to welt into a position to engage said another butt of the needle and move the needle to a knit position or into a position to engage said another butt and move the needle to a tuck position; another needle including a butt engageable with said wing cam when said another needle is permitted to welt, the said another needle being movable across the gap between the wing and stitch cam after engagement with the wing cam and said another needle also including a second butt; a second bridging cam engageable with said second butt of the said another needle during said movement of said another needle between the wing and stitch cam whereby movement of such another needle toward a tuck or knit position is restricted while in said gap; and a second adjustable cam movable from a position permitting said another needle to welt into a position to engage said second butt and move said another needle into a knit position, or into a position to engage said second butt and move said another needle to a tuck position.

10. The combination of claim 9 including a guard cam movable with each adjustable cam; said second bridging cam extending into the path of movement of the guard cam which is movable with the second adjustable cam, and the other bridging cam extending into the path of movement of the other guard cam movable with the other adjustable cam; the second bridging cam being retractable into a position wherein interference with the guard cam movable with the second adjustable cam is avoided, and the other bridging cam being retractable into a position wherein interference with the other guard cam is avoided.

* I l 1 l 

1. In camming for a knitting machine, the combination comprising a wing cam; a stitch cam separated by a gap from the wing cam; a needle with a butt engageable by both said wing and stitch cams when the needle is permitted to welt, said needle being movable beyond the trailing edge of the wing cam and across said gap to the stitch cam, the needle also including another butt; and a bridging cam engageable with said another butt throughout movement of the needle between the trailing edge of the wing cam and the stitch cam whereby movement of the needle toward a knit or tuck position is restricted while the needle moves across said gap.
 2. The combination of claim 1 wherein the bridging cam is of a length sufficient to be engageable with said another butt in positions of the needle beyond said gap.
 3. The combination of claim 1 including an adjustable cam movable from a posiTion permitting said needle to welt, into a position to engage said another butt of the needle and move the needle into a knit position or into another position to engage said another butt of the needle and move the needle into a tuck position; and a guard cam to limit the uncontrolled flight of said needle from the adjustable cam, said guard cam being movable with the adjustable cam; the bridging cam extending into the path of movement of the guard cam but being retractable into a position wherein interference with the guard cam is avoided.
 4. The combination of claim 3 including means for holding the bridging cam in a retracted position.
 5. The combination of claim 3 including means defining the operative position of the bridging cam.
 6. The combination of claim 3 including means positively preventing any substantial movement of the bridging cam beyond an operative position.
 7. The combination of claim 1 including an adjustable cam movable from a position permitting said needle to welt into a position to engage said another butt of the needle and move the needle into a knit position or into another position to engage said another butt of the needle and move the needle into a tuck position; and a guard cam to limit the uncontrolled flight of said needle from the adjustable cam; said guard cam and bridging cam being affixed to and movable with the adjustable cam.
 8. The combination of claim 1 including an adjustable cam movable from a position permitting said needle to welt into a position to engage said another butt of the needle and move the needle into a knit position or into another position to engage said another butt of the needle and move the needle into a tuck position; and a guard cam to limit the uncontrolled flight of said needle from the adjustable cam, said guard cam being movable with the adjustable cam and the bridging cam extending into the path of movement of the guard cam; and cam section means for supporting all of the cams; the bridging cam being affixed to and stationary on said cam section means but being detachable therefrom to permit its removal from the path of movement of the guard cam.
 9. The combination of claim 1 including an adjustable cam movable from a position permitting said needle to welt into a position to engage said another butt of the needle and move the needle to a knit position or into a position to engage said another butt and move the needle to a tuck position; another needle including a butt engageable with said wing cam when said another needle is permitted to welt, the said another needle being movable across the gap between the wing and stitch cam after engagement with the wing cam and said another needle also including a second butt; a second bridging cam engageable with said second butt of the said another needle during said movement of said another needle between the wing and stitch cam whereby movement of such another needle toward a tuck or knit position is restricted while in said gap; and a second adjustable cam movable from a position permitting said another needle to welt into a position to engage said second butt and move said another needle into a knit position, or into a position to engage said second butt and move said another needle to a tuck position.
 10. The combination of claim 9 including a guard cam movable with each adjustable cam; said second bridging cam extending into the path of movement of the guard cam which is movable with the second adjustable cam, and the other bridging cam extending into the path of movement of the other guard cam movable with the other adjustable cam; the second bridging cam being retractable into a position wherein interference with the guard cam movable with the second adjustable cam is avoided, and the other bridging cam being retractable into a position wherein interference with the other guard cam is avoided. 